TWAInv2

Invertebrates, Algae and Vascular Plants of The Tropical West Atlantic: Bahamas to Brazil, Part 2

To: Part 1, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9,

Bob Fenner

Sponges

Sponges, Phylum Porifera Classification:

Sponges comprise the phylum Porifera, whose name means "bearing openings"; an allusion to their overall porosity and general mode of feeding (filtration), respiring, excreting wastes while whipping water in through openings in their body walls. Sponges are the simplest form of multicellular animals, just up from protozoans and down from cnidarians (stinging-celled like corals and anemones) in most taxonomic schemes. They don't, in fact, have tissues or organs. Their cells are somewhat unspecialized and quite independent, more like a commune or colony than a single animal.

There are about 5,000 identified marine species of sponges. There are a few ambulatory types but almost all are attached permanently to hard or soft substratums. Sponges are found worldwide, mostly in shallow waters; in all colors and shapes and sizes, from a thumbnail to a washtub. Some are cylinders, others vase-like; most are crustose and irregular (shown: a Caribbean sponge scene off of Tobago, Sponge scene in Tobago, Carib.).

The Porifera live up to their names by having a characteristic arrangement of specialized cells imbedded in a spongy matrix (spongin), incurrent pores (ostia) formed by porocytes allow water into an open space (atrium) in their bodies and out one or more larger openings (oscula-ae). Their outer walls are supported by non-living calcareous or siliceous structural elements called spicules. Along with proteins these are the sponge skeletons of bathroom sponges derived from biological sources.

Agelas conifera, the Brown Tube Sponge. Typically smooth walled, brown to tan in color, smooth, velvety in appearance. Grow in clusters, joined at base. Bonaire pic.

Aplysina archeri, the Stove Pipe Sponge. Long thin tubes of lavander, gray or brown. Soft to the touch. Tropical West Atlantic. Bonaire pic.

Aplysina cauliformis, the Row Pore Rope Sponge. Long rows of excurrent siphons. Occur in tints of purple, reds. Antigua photo.

Aplysina fistularia, the Yellow Tube Sponge. Yellow to orange tubes that bear antler-like growths in shallows, and grow longer w/o these "antlers" in increasing depths. Don't touch! Purple color stains hands for days. Right: shallow colony in Bahamas and deeper one in Belize . Below: young colonies in Antigua and Bahamas, and a large one in Bonaire.

Callyspongia plicifera. Azure Vase Sponge. Bahamas pic.

Cinachyra sp. Orange Ball Sponge. Tropical West Atlantic, to 100 foot depth, under ledges, in protected areas. To about 1/2 foot diameter orange ball-shapes, with many excurrent siphons riddling their surface. St. Thomas image.

Clathrina canariensis Yellow Calcareous Sponge (Class Calcarea). A delicate, small (to four inches) bright yellow organism, made up of intertwined tubes. Tropical West Atlantic; usually found within caves or other shady spots. St. Thomas, U.S.V.I.

Cribrochalina vasculum, the Brown Bowl Sponge. Bahamas pix.

Diplastrella megastellata Red-Orange Encrusting Sponge. Caribbean. To ten inches, seventy five feet in depth. Found in shaded areas, even under rocks, overhangs. St. Thomas, U.S.V.I.

Ectyoplasia ferox, Brown Encrusting Octopus Sponge. Occurs as both encrusting and in multiple-armed arborose morphologies. Bahamas pic.

Iotrochota birotulata, the Green Finger Sponge. Made up of finger-like branches, often covered with Golden Zoanthids (as shown). Bahamas and St. Lucia pix.

Ircinia felix, Class Demospongiae. Stinker Sponge. Light gray or brown encrusting globes, 6-12 inches in diameter. Conspicuous hexagonal markings on surface. Smells very bad on removal from water. Cozumel pix, close-up by Diana.F

Niphates digitalis, the Pink Vase Sponge. Pink, blue, gray. To twelve inches in height. Bahamas and Cozumel pix. The second one acting as a host/commensal for the zoanthid Parazoanthus parasiticus.

Phorbas amanthus, Red Sieve Encrusting Sponge. Cozumel pic by Diana.F. Size 6-18 in. Bright red, with surface showing numerous craters (raised circular sieve like areas) and small incurrent pores around protruding excurrent openings. Reacts to touch by closing openings and pores.

Siphonodictyon coralliphagum, the Variable Boring Sponge. Not for reef aquariums. Appears in various physical forms, fingers to bowls, to encrusting patches. Bores into live corals. May appear encrusting or tublular. Cancun pix.

Spirastrella coccinea, a relatively common encrusting sponge, here in Cozumel, a close-up by Diana.F.

Tedania ignis, Fire Sponge. Tropical West Atlantic down to 35 ft. 4-12 inches overall. Distinctive volcano-like excurrent openings. Orange to bright red in color overall. Irritating to the touch. Bahamas and Bonaire pix.

Xestospongia muta, the Giant Barrel Sponge. To six feet in height. Bahamas pic.

To: Part 1, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15,

Please visit our Sponsors